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Discussion Starter #1
Hello everyone. I am new to the sight but do have a question about the 99 4.0 Jeep Grand Cherokee. So it has come to my attention that there is an oil leak coming from the front of the engine. Found it the other day while going uptown. When having a look it seems to be coming from the front of the engine primarily from what I believe is the crankshaft gasket. So two questions.
1) Is it difficult to fix this procedure
2) Any special tools I will need to complete this?

I have worked on cars beforehand and have replaced oil pan gaskets in the past but never have replaced a crankshaft leak. Thanks.
 

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I would suggest that you thoroughly clean the front, bottom and sides of the engine. Then run engine at slow driving speed for just a few miles and then inspect. Wind currents generated around the engine at highway speeds can cause oil leaks to appear in different places and mislead you as to the source.

I would carefully inspect the timing cover and oil pan gasket and make sure those are not leaking at first inspection. If you are confident that the leak is at the front crankshaft seal, then proceed to replace that seal. Here is a link to a YouTube video on replacing the front crank seal on the 4.0 liter engine. Only special tool is the pulley / harmonic balancer that is necessary.

Front crank seal replacement write up with pics !!
 

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Welcome to Allpar. Sometimes when a large area is wet from a leak, I have had to degrease and rinse the area to watch where the leak originates.
There are UV dyes that can be added to fluids so that more difficult leak trails can be visually diagnosed. It is safe for engines.
Leaks tend to move downward from gravity and rearward from road draft.
Here is the section on the 4.0L beginning on p. 9-16. Special tools are shown for front seal service:
http://oskin.ru/pub/chrysler-dodge/manuals/Service Manuals/1998_ZG_Jeep_Grand_Cherokee_Diesel_Versions_Include/english/ezg_9.pdf
 

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Discussion Starter #5 (Edited)
Thank you both for the reply. After cleaning a large array of leaking oil I took the car to town and back. After the drive, I found the leak not to be the crankshaft, but the oil pan. There seems to be a very small fracture on the exposed portion of the gasket very close to the camshaft. It seems to be the area of the oil pan gasket right behind the cam.
 

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Discussion Starter #7
Regarding the leak, I found the source coming from the frontal groove of the oil pan gasket. In the 4.0s this seems to look like this in the photo
 

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Being a new member, you may have a waiting period before you can post an image. I would place the image in a photo hosting website and post us a link to it.
 
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